‘Waste’ is generally identified as goods or material that are perceived to be mostly valueless. However, objects that are perceived to be waste based on consumers’ object valuation can be redefined to create value. This requires a multitude of efforts using different strategies in waste prevention and management. This book is an edited collection of various chemical approaches used for valorization of solid wastes, particularly, waste electrical and electronic equipment, plastic waste, and agro-residue waste, that provide research insights into the concept "waste-to-energy". Covering a variety of interdisciplinary topics on waste treatment and resource recovery makes the book one for all that serves as an excellent reading material for engineers, science scholars, entrepreneurs, and organizations who are working in the field of waste management.